Residents at Jalan Kolam Air were badly affected as flood waters rose as high as one metre. A resident, Ravi Chandran, 43, said it was not the first time the area had been flooded. The residents live beside Sungai Batu and flash floods have been occurring for years.

According to the Kuala Lumpur City Hall flood information centre, the floods began at 5pm after a downpour.

Enforcement officer Chief Insp Lamli Musa said the flood waters began to recede after the Smart Tunnel was closed to traffic to enable flood operations.

PETALING JAYA: In just two hours on Tuesday, Kuala Lumpur saw more rain than it normally would in two months.

Not just that. The rain, which started in the afternoon, was so intense that it caused Sungai Gombak to quickly swell and overflow.

This resulted in the flood havoc in several parts of Kuala Lumpur. Vehicles in underground car parks were submerged and thousands of motorists were caught for hours in a traffic gridlock that continued past 9.30pm.

Describing the rainfall as exceptional, Department of Irrigation and Drainage director-general Datuk Ahmad Husaini Sulaiman said 75mm of rainfall was recorded within two hours.

“Normally, we receive about 30mm in a month. The rain (Tuesday) was so heavy and the intensity so great that Sungai Gombak could not cope with the buildup of water.

“Coupled with the capacity of Sungai Damansara and the drainage system in the city, the amount of water was just too much over a short period of time.

“Tuesday’s situation was serious and caused a lot of distress to many people, and we want the public to understand why it happened,” he said yesterday.

The Stormwater Management and Road Tunnel (SMART), generally seen as the answer to the city flood woes, was not “utilised” as it was designed to divert excess water from Sungai Klang.

Ahmad Husaini said SMART was not closed to traffic as the concentration of the rain was not over Sungai Klang.

However, he said, once the Batu and Jinjang flood retention ponds were completed by the middle of this year, such situations could be averted.

The ponds have an increased capacity of 4.5 million cubic metres and 2.5 million cubic metres respectively, enough to hold excess water from Sungai Gombak and Sungai Keroh.

A Meteorological Services Department officer said Tuesday’s rain was due to weak and variable winds which caused an unstable atmosphere.

“We are now towards the end of the north-east monsoon which brings about sudden changes of atmosphere. The inter-monsoon season is expected to start in April,” he said.